1. Field of the Invention
A locking differential includes a pair of annular collinear axially-spaced clutch members that are normally biased together by a resilient disc and friction pack assembly toward a cross pin that extends diametrically across the central chamber of a cylindrical housing driven by the drive shaft of a vehicle, thereby to drive a pair of side gears and the output shafts splined thereto. The cross-pin extends within operating cam grooves contained in the adjacent faces of the clutch members, such that when the rotational velocity of one output shaft exceeds that of the other by a predetermined amount, the friction pack assembly of the faster shaft is operated to a non-compressed condition, thereby to disengage the over-running output shaft from the drive shaft. The resilient disc means may be annular wave springs, or resilient disc springs.
2. Description of Related Art
As evidenced by the prior U.S. patents to Schou U.S. Pat. No. 4,498,355, Zentmyer U.S. Pat. No. 5,413,015, Dissett U.S. Pat. No. 5,715,733, and Valente U.S. Pat. No. 5,836,220, among others, it is known in the patented prior art to provide locking differentials for vehicles that operate to disengage from a drive shaft a driven output shaft that overruns another output shaft by a predetermined rotational velocity. Furthermore, in the prior patents to Valente U.S. Pat. No. 5,727,430 and Dissett et al U.S. Pat. No. 6,688,194, it has been proposed to include in these locking differential arrangements axially-compressible friction pack means for connecting and disconnecting the annular clutch members of the differential with the side gears that are splined to the output shafts, respectively.
In these known prior art arrangements, in order to achieve the desired differential operation, it is conventional to use a plurality of compression springs for biasing apart the clutch members relative to a cross-pin arranged therebetween. Normally, first ends of the clutch springs are mounted in circumferentially arranged first bores contained in the face of one clutch member, with the second spring ends either extending within corresponding second bores contained in the face of the other clutch member, or into engagement with pins that extend within these second bores.
Various attempts have been made to improve differential operation by reducing backlash. Furthermore, continuing efforts have also been made to reduce the cost of the components of the differential and to simplify the assembly of the components within the central chamber of the differential housing. The present invention was developed to provide improved product operation with attendant cost reduction, and to avoid the drawbacks of the known locking differentials. The present invention is characterized by substituting for the prior compression springs that served to bias the clutch members outwardly apart, resilient disc means that are mounted concentrically about the side gears for biasing the clutch members inwardly together.